Twisting noncircular blanks for drills, etc.



March 18, 1-930.-

F. T. HARRINGTQN ETC TWISTING NONCIRCULAR BLANKS FOR DRILLS Filed April 25, 1928 3 Sheets-Sheet gwwmtoz ZVInF/P/JVGM March 18, 1930.

F. T. HARRINGTON 1,750,776 TWISTING NONCIRCULAR BLANKS FOR DRILLS, ETC

Filed April 25, 1928 3 Sheets-Sheet 2 March 18, 1930.

TWISTING N F. T. HARRINGTON ONCIRCULAR BLANKS FOR DRILLS, ETC

Filed April 25. 1928 MW A 5 Sheets-Sheet 3 Patented Mar. 18, 1930 UNITED stares mains T, HARRINGTON, or DETROIT, MICHIGAN, ASSIGN'OR To WHITMAN & B RNES,

Parser GFFE CE Z INC, OF DETBOI' I, MICHIGAN, A CORPORATION OF MICHIGAN I i f TWISTING NONGIROULAR BLANKS FOR DRILL S, ETC.

Application filedApril 25,

This invention relates to machines 'for twisting drill stock and drill blanks in the manufacture offluted twist drills, reamers, and similar articles of spiral form.

The invention aims to provide improved means for twisting thestock after the fiuting operation, enabling the operation to be performed quickly and with a minimum of manual labor, andproducing a more uniform product than heretofore.

A further object of the invention is to provide for readily changing the dies to take drill stock of various sizes, and for adjusting the amount of twist to suit'the work in hand.

Other aims and advantages of the invention appear hereinafter in connection with the description of the illustrative embodi ment shown in the accompanying drawings, wherein Fig. 1 is a side elevation of a twisting machine; y

Fig. 2' is a front elevation thereof;

Fig. 3 is a plan view; 1

Fig. 4:, is a vertical sectionthrough the twisting dies and gears for operating them, taken on the line H in Fig. 3;

Fig.5 is a horizontal cross-section of the same, on'the line 5 5 in Fig. 4, omitting the supporting housing and Figs. 6 and 7 are views of the fluted stock 1 before and after twisting, respectively.

' abutments.

In drill-twisting machinesas heretofore constructed, the 'rotary diesthat grasp the heated stock are caused to turn by twisting onev end of the stock until each die comes to a stop against a corresponding abutment, thereby defining the desired spiral, and any change in the angle of lead of the drill re quires changes in the. positions of all of the Moreover, the different por'-' tions of the stock twist at different rates because the temperature is not uniform from end to end, and the coolerends do not take as much twist as the middle portion.

In my improvedmachine, the twisting dies are caused to'rotate at proportional rates of speed, eachthrough the properangle to produce the twist desired, by, means of gearing from a common driving means,jwhereby the same degree of twist is simultaneously apvenience made in the form ofrings, and are 1928. Serial No. 272,839.

plied to all parts of'the stock irrespective of slight differences in temperature or other factors tending to produce uneven twisting, andthe finished productis given a uniform spiral shape. 7 A g Referring to the drawings, which disclose a preferred form of the invention, the stock; lOis fluted (see Fig. 6) and the twisting dies 11 (see Figs. 4 and 5) are shaped to fit loosely in the flutes and are mounted in pairs in superposed rotary carriers 12, assembled in a. frameor housing 13. The carriers 12 have central openings in alinementwith top andbottom holes 14 in the housing through which I the heated stock may be introduced, and. the carriers and housing are provided with interengaging ribs 15 and grooves 16 for maintaining them in axial alinement, and with a series of positioning holes 17 which are so disposed as to be in alinement when the dies are in straight alinement to receive the fluted the housing 13 is removed from the machine and for testing the alinement prior toinserting a piece of stock. I a The carriers 12' are provided; withgear V teeth Ont-heir peripheriesand are caused to rotate inlunison and'at proportional-rates of. speed bya series of'timing gears 19 securely keyed on a vertical. shaft 2Qmounted inethe frame 21 of the twisting machine.

V ht e-v .dlate idler gears22, of varying sizes to suit the spaces between the carriers 12 and timing gears 19, transmit the motion of the respec, tive timing gears tothe carriers, the 'latter' being rotated each at the same peripheral orv pitch line speed as that of the corresponding; 7

timing gear. The idlergears 22 are for con journaled on eccentrics 23, which are secured against rotation upon a vertical. shaft2 fixed, in the machine Figs. 4cand5. p i

The nestof gears. shown in the drawings frame, as illustrated in and timing gears, all of the carrier gearsgfor convenience being made of uniform pitch} .95 comprises twenty-eight sets of carrier, idler V driving ratio with respect to said carrier gears for turning the latter at progressively increasing angular velocity conforming to the degree of twist desired, said dies being changeable to suit different shapes and sizes of stock.

5. A machine for twisting non-circular drill blanks and the like, comprising a series of rotatable carriers having axial openings to receive the work, gear teeth on said carriers,

and a series of gears of progressively increasing driving ratio with respect to said carrier gears for turning the latter at progressively increasing angular velocity conforming to the degree of twist desired, said carriers and gears being operatively connected by a series of interposed independently rotatable idler gears of progressively varying diameter.

6. A machine for twisting non-circular drill blanks and the like, comprising a series of rotatable carriers having axial openings to receive the work, gear teeth on said carriers, and a series of gears of progressively increasing driving ratiowith respect to said carrier gears for turning the latter at progressively increasing angular velocity conforming to the degree of twist desired, and said carriers being mounted in a removable housing independently of said gears.

7 A machine for twisting non-circular drill blanks and the like, comprising a series of rotatable carriers having axial openings adapted to receive and non-rotatably engage the work, means for rotating said gears in synchronism at progressively increasing rates of angular movement, and means for reversing the direction of rotation of said carriers to restore them to their original alined position.

8. A machine for twisting non-circular drill blanks and the like, comprisinga series of rotatable carriers having axial openings adapted to receive and non-rotatably engage the work, means for rotating said gears in synchronism at progressively increasing rates of angular movement, and automatic means for reversing the direction of rotation of said carriers to restore them to their original alined position. I

9. The process of twisting non-circular drill shapes and the like which comprises grasping the work at uniformly spaced points along its length and twisting it at positively controlled progressively and uniformly increasing rates of angular movement applied to said points simultaneously, whereby the amount of twist thereby produced is uniform in the intervals between said points throughout the twisting operation.

In testimonywhereof, I have signed my name to this specification.

FERRIS 'lI'. HARRINGTON. 

